Recently, at a time i was kind of bored, i started exploring some of dyn4j's source code, and found couple of things that could be changed. Note those are very minor stuff that could be skipped as well, i was just bored

And finally i saw a lot of invocations of Math.min(double, double) and Math.max(double, double). Maybe you should replace those with two custom made equivalent methods, because they made quite some pointless (for the case) checksCode from Math.java: